Dog infertility

Hello. Sorry for my English. My dogs probably infertility, she cannot get pregnant a second time. The dynamics of progesterone before mating and during the first month after are normal, the cycle is not disrupted, the mating date was chosen taking into account the level of progesterone. She has a cyst on one ovary. The only symptom is that estrus begins on the second day from the start of vaginal bleeding and 10 days before ovulation, according to the results of cytological smears from the vagina. What should we pay attention to when planning our next mating to increase the likelihood of pregnancy? She is 6 year old. The cyst was aspirated under ultrasound guidance.

Hello - thankyou for this fascinating question .  Heat has 4 stages in a dog

1. Pro-oestrus  lasts 7-10 days.  There is bleeding.  Female is interested in males and attracts them, but does not allow mating
2. oestrus - heat.  Lasts 5-10 days.  Bleeding gets less and stops.  Females allow mating.  Ovulation occurs, usually after mating
3. Di-oestrous.  Lasts up to 120 days.  The female is pregnant or 'resting' in this period.  Progesterone is high, either because of pregnancy or because the remains of the follicle persist after ovulation.
4. anoestrus - resting between cycles.

Thus you can see that, although women bleed late on in the cycle when they have not become pregnant, this is not the pattern with dogs.  If the opportunity has presented, scanning should always be done at the appropriate times post-mating in order to be certain that there is no pregnancy; if not pregnant, the progesterone phase may simply be elongated dioestrous and this may have implications for the risk of e.g. pyometra.  Your vet or their lab pathologist may check this for you - please do not take my word for it as it is not my specialist area (most UK dogs are speyed well before reaching this age). Six is quite advanced in years for many female dogs to be breeding in any case.  Birth may be much harder on the mother and in some cases, your vet may consider another mating to be unethical. Reasons for lack of conception can include veneral disease, damage to the womb and canal, changes to the ovaries, persistent pregesterone environment, cysts, stress, adhesions from previous pregnancies, age and so on. We would urge you to ask your vets lots of questions about this situation before considering breeding from your female.  Their friendly lab pathogist may be able to help to source some up to date, objective statistics in order to lend weight to any claims that they might make.

My apologies - I reread that and that last line didnt read as I intended it!  What I meant was that if it isn't their area either, your vets can work with pathogists (or other field experts eg university specialists) in order to ensure that any information they give to you regarding your dogs' condition, is up to date and backed up by recent ideas and statistics.